Most post updates had the D35 anyway. So it might well be the exact same diff already.
Compare the diff covers.
D35
8.25
Notice how the 8.25 does not have as big a depresion around the fill plug and the housing is flat under the cover.
If you were to replace the 8.25 with the D35, you will need a longer driveshaft as they D35 has a shorter pinion. Everything else is the same or can be swapped across I have been told.